Self-stiffened flexible kite

ABSTRACT

There is disclosed for the purpose of longitudinally bracing and stiffening a flexible kite of the type known as an &#39;&#39;&#39;&#39;Allison Sled&#39;&#39;&#39;&#39;, rear-standing flanges substantially perpendicular to and integral with the lines of contiguity between a central air-foil panel and the tether panels laterally associated therewith.

United States Patent 1191 Checkley Jan. 14, 1975 [54] SELF-STIFFENED FLEXIBLEKITE 2,484,316 10/1949 Simons 244/153 R 1 1 111141101: D1111 checkley, Box 9081, 5:335???) 313% 131311131 13111113121123 5 Seattle, WaSh- 98119 2,783,958 3/1957 Caroff....' 244/153 R 22 Filed: May 11, 1973 Primary Examiner-Trygve M. Bl1x PP 3591312 Assistant Examiner-Paul E. Sauberer 52 Us. c1 244/153 R 1 1 ABSTRACT I [51] Int. Cl. 1364c 31/06 There is disclosed for the purpose of longitudinally [58] Field of Search 244/15'3 A, 153 R, 154, bracing and stiffening a flexible kite of the type known 244/155 R as an Allison Sled, rear-standing flanges substantially perpendicular to and integral with the lines of [56] References Cited contiguity between a central air-foil panel and the UNITED STATES PATENTS tether panels laterally associated therewith.

1,105,058 7/1914 Bochau 244/153 R 10 Claims, 16 Drawing Figures SELF-STIFFENED FLEXIBLE KITE BACKGROUND OF THE INVENTION A flexible kite is illustrated in the Allison Pat. No. 2,737,360 issued Mar. 6, 1956, which has met with considerable success among kite flyers and has come to be known variously as the Allison Sled or the Scott Sled", after the late Walter Scott who did much to popularize the design.

Following the teachings of Allison one can produce a polymorphic kite which is capable of assuming a variety of shapes in the air in response to fluctuating air streams. The main features of such a kite are a central air-foil panel which is transversely flexible but longitudinally stiff and which has laterally disposed tether panels. In plan such a kite is generally hexagonal in shape. Customarily longitudinal stiffness is provided by securing substantially rigid elongated members, formed of wood, plastic or metal as strips, dowels or tubes, in or on the kite between each tether panels and the adjacent edge of the air-foil panel. It has been found that the production, transport and distribution of an inexpensive and simple kite employing the principles of the Allison Sled is complicated by the necessity to use the disclosed substantially rigid elongate members. They generally require pockets for their insertion. Being long and thin they can be easily damaged unless supplied with a protective tube or package. And they are costly.

SUMMARY OF THE INVENTION The primary objects of this invention have been the provision in an Allison Sled kite of means for longitudinally bracing the edges of the air-foil panel which may be derived from the basic sheet material out of which the kite is produced; which obviate the need for discrete or separate stiffening strips; which may be easily formed by the unskilled, large as well as small; which do not impede or affect the air currents impinging on the kite during flight; and which, despite being laterally non-stiff are very effective to stiffen the kite substantially normal to its face along the edges thereof.

The accomplishment of these and other objects and advantages will become apparent during the course of the following description in which is set forth a preferred embodiment of the invention and various alternatives thereto.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the kite in flight;

FIGS. 2,3,4 and 5 schematically illustrate the steps in producing a kite from a panel of sheet material;

FIG. 6 illustrates an alternate mode of assembly and rigidifying the kite;

FIGS. 7,8 and 9 show how the kite may be formed out of paper bags; and

FIGS. 10 through 16 illustrate in cross-section a variety of stiffening flanges.

DESCRIPTION OF THE PREFERRED EMBODIMENT:

The kite shown in FIG. 1 comprises the air-foil panel 20 having leading edge 22 and trailing edge 24. Panel 20 is rectangular as shown. Each side edge of panel 20 has contiguous thereto a tether panel 26 of triangular shape having a base equal to the length of the side edge of panel 20. In the preferred form, tether panels 26 are obtuse triangles having their apices truncated as shown in the drawings and located nearer the leading edge 22 than the trailing edges 24 of panel 20. A tether line 28 secured to each panel 26 at 62 extends to juncture 30 at which point the flight line 32 is attached. The tether lines 28,28 effectively form a bridle between the flight line 32 and the tether panels and function to define a lateral line of restraint from which tension forces radiate across the panel 20 and tetherpanels 26 when flight is attained. In flight the kite tends to pivot and longitudinally shift about the line extending transversely of the kite through the points of attachment 62,62 at the apices of the tether panels. Such pivoting and longitudinal shifting is effected and controlled by the air stream on the faces of panels 20 and 26,26 which shape the kite in flight and by the air flowing over and past the edges I of the kite.

The air-foil panel 20 and tether panels 26,26 of this kite are cut from any light sheet material reasonably air impervious. Such include'tight-weave fabrics of both the woven and non-woven varities, plastic films such as polyethylene and polypropylene types, and preferably paper where low cost is a major consideration. With such sheet materials it is necessary to provide means for longitudinally bracing the air-foil panel so that its side edges remain straight during flight. This is best accomplished by providing a stiff flange 34 standing rearward from the air-foil panel at and substantially perpendicular to each line of contiguity between the airfoil panel and. the laterally disposed tether panels.

FIGS. 1-5 illustrate how an inexpensive but highly effective and serviceable kite may be produced from a single sheet of paper. In this form a pre-printed rectangular sheet or blank 36 has thereon the outline of the air-foil panel 20 (medially creased at 38 for compactness) and the tether panels 26,26. Creases 40,40 divide marginal portions 42 of the air-foil panel 20 and contiguous marginal portions 44 of the adjacent tether panels 26,26. Across the bottom of sheet 36 is outlined a pair of strips 46,46 which later, when cut away, serve as tail streamers for the kite. I

In FIG. 3 is shown how sheet 36 is cut apart to form the various parts of the kite. Usually streamers 40,40 are first removed and laid aside. Then the air-foil panel with attached tether panels is'cut to the preprinted hexagonal outline. With the parts of the air-.foil panel20 folded at crease 38 and following the outline 46 a cutout opening 48 is formed in the lower center of panel 20.

In this preferred embodiment mucilage is applied to the blank 36 in strips 50 adjacent creases 40; in patches 52 on the upper corners 58 of the blank; and in patches 54 at ends of tail streamers 40. It will be apparent that certain portions 56,58 of the blank may be discarded -as waste when the outlined cutting has been completed and patches 52,52 have been cut out and attached as bridle reinforcements.

To assemble the kite one first moistens a mucilage strip 50 at one side and then closes the marginal portions 42,44 together by closing fold or crease 40. By rubbing the creased portions firmly (see FIG. 4) the mucilage will set and adhere evenly to form stiffening flange 34. The operation is repeated on the opposite side edge of panel 20 and the assembly will be as shown in FIG. 5 when reinforcement tabs 52 are applied at the apices of tether panels 26. Holes 62 in tabs 52 receive the ends of tether lines 28. The tail streamers 40 may be attached by means of their mucilage pads 54 to the lower endsofflanges 34 when extra stability in a strong breeze is required.

The stiffening flange 34 just described is shown enlarged in FIG. from which it will be seen that the marginal portions 42,44 are securely joined and longitudinally stiffened in one plane by the interposed adhesive or mucilage strip 50. Alternate forms of stiff flanges 34 are shown in FIGS. 11 15. In a kite formed as in FIG. 11 the marginal portions, although not integral, are joined by mucilage 50. In FIG. 12 a staple 70 secures the panel margins together. In FIG. 13 the external portion of flange 34 is capped or covered by a creased adhesive tape 72 and, as further stiffening is desired tape 74 may be attached to span along the line contiguity at the faces of the adjacent air-foil and tether panels. FIG. 14 shows a kite form in which only spanning tape 74 is used to secure flange 34. A combination involving a strip of stiff sheet material 80 or mucilage interposed between marginal portions 42,44 and secured with the spanning strip of tape 74 produces a very strong stiff flange 34.

The assembly operation of a kite employing tape strips 74 as illustrated in FIG. is also shown. In an alternate method of reinforcing to the outer corners of tether panels strips of adhesive tape 76 are folded over and applied to opposite edge faces of the tether panels to reinforce the holes 62 and prevent the panel covers being torn away.

Kites according this invention need not always be made from sheet stock. It has been found, as shown in FIGS. 7 9, that the elements of this style kite may be formed from collapsible paper bags of common usage. The bag 80 has creased and infolded sides, or gussets, 82 which when a pre-printed outline as indicated is followed, can be adhesively joined together toform the longitudinally bracing, rear-standing flanges between tether panels 84 and air-foil panel 86. In similar manner kites according to this invention may be produced from the rectangular bottom paper bag 90 shown in FIGS. 8 and 9, to include the elements to provide tether panels 92, air-foil panel 94 between which are the infolded margin portions 96 and 98 which serve as part of the reinforcing and bracing flange for the completed kite.-

Referring to FIG. 16 the main panel and tether panel 26 are contiguous at the crease 21 and, in this form, devoid of interposed fold forming the stiffening flange 34 as described in connection with FIGS. 10 through 15. The flange 34 is comprised of two angular members 100 and 102 having adhesive layer 104 disposed between the outstanding legs 106 and adhesive layers 108 between each flange foot portion 110 and the back faces of panels 20 and 26. The adhesive layers 108 and 104 may be integral throughout flange 34 as shown they may be discrete strips of adhesive.

It will be understood that the primary function of the flanges 34 will, according to the various systems shown in FIG. 10 16, have varying degrees of lateral stiffness and substantially similar degrees of longitudinal stiffness in the plane in which they lie. The absence of lateral rigidity is relatively unimportant whereas the described longitudinal stiffness is important. In flight the air-foil panel flexes or bows transversely in response to the wind or breezes but it is very desirable to avoid longitudinal flexing or bowing of the air-foil panel. Rearstanding flanges 34 as disclosed and described serve as braces along the lines of contiguity between the air-foil and tether panels and maintain the desired air-foil configuration.

The opening 46 may or may not be used. In stiff breezes its use is desirable as it releases and vents some of the air pressures in the lower portion of the air-foil panel 20 which provides certain stabilizing functions.

tether panels above the transverse median of the kite causes it to assume an angular disposition in the air stream. Initially the kite will wobble or rock but it rapidly stabilizes with leading edge substantially horizontal and facing into the air stream. As air flows, rearward across the front of the air-foil panel shaping it, air also passes over leading edge 22 creating a low pressure area above and behind the air-foil. A combination of these forces creates in this kite stability and flexibility of surprising magnitude. As height is desired line 32 is payed-out in the conventional manner. In turbulent or strong air streams it is often desirable to increase stability. This can be accomplished by opening vent 48 if not previously cut away, and by adding the streamers- 40,40. By reason of the lateral dispositions of the streamers it has been found that they may be surprisingly short and narrower than as shown.

It will be observed that the kite in its preferred and alternative forms described provides the features and accomplishes the desired objectives set forth above. It will also be observed that the features of the kite may be modified as to shape and size, and as to proportions to meet varying conditions. All such as fall within the spirit and scope of the invention without departing from the principles involved are intended to be covered by this patent.

What is claimed is:

1. In a kite of the type wherein an air-foil panel providing a leading edge and a trailing edge, includes a tether panel oustanding contiguous to each side edge of said air-foil panel between said leading and trailing edges and there is a means for bracing said air-foil panel against longitudinal flexure, and said tether panels by tether lines are joined to a flight line, the improvement, wherein:

said means for longitudinally bracing said air-foil panel comprises a flange normally weak under longitudinally applied compressive forces rearstanding substantially perpendicular to each line of contiguity and extending the full length of said airfoil panel and the tether panels associated therewith, said flange being uninterrupted throughout its full length and width, and said flanges, during flight of said kite, being stiffened by tensile forces applied thereto at the lines of contiguity by the air distendair-foil panel and tether panels, and said flanges stiffening said panels against bowing along the lines of contiguity. 2. The kite structure of claim 1 in which each flange is formed of a side marginal portion of the air-foil panel and a side marginal portion of an associated tether panel, said marginal portions being juxtaposed and secured together against relative movement.

3. The kite structure of claim 2 in which saidjuxtaposed marginal portions are secured together by adhesive means.

4. The kite structure of claim 3 in which the adhesive means comprises an adhesive layer interposed between said juxtaposed marginal portions.

5. The kite structure of claim 3 in which the adhesive means comprises a tape spanning edges of said juxtaposed marginal portions.

6. The kite structure of claim 2 in which the air-foil and the associated tether panels are formed of a single piece of sheet material folded to form said flanges.

7. The kite structure of claim 6 in which the sheet material is selected from the group consisting of paper, plastic or fabric having stiffness substantially equivalent to 25 lb. M.G. Kraft or greater.

8. The kite structure of claim 6 in which each flange includes longitudinally stiffening means interposed between said marginal portions normal to the lines of contiguity.

9. The kite structure of claim 8 in which each said stiffening means comprises a strip of stiff sheet material.

10. The kite structure of claim 8 in which there is a strip of tape spanning the length of each line of contiguity at the side margin of-the air-foil panelf 

1. In a kite of the type wherein an air-foil panel providing a leading edge and a trailing edge, includes a tether panel oustanding contiguous to each side edge of said air-foil panel between said leading and trailing edges and there is a means for bracing said air-foil panel against longitudinal flexure, and said tether panels by tether lines are joined to a flight line, the improvement, wherein: said means for longitudinally bracing said air-foil panel comprises a flange normally weak under longitudinally applied compressive forces rear-standing substantially perpendicular to each line of contiguity and extending the full length of said air-foil panel and the tether panels associated therewith, said flange being uninterrupted throughout its full length and width, and said flanges, during flight of said kite, being stiffened by tensile forces applied thereto at the lines of contiguity by the air distendair-foil panel and tether panels, and said flanges stiffening said panels against bowing along the lines of contiguity.
 2. The kite structure of claim 1 in which each flange is formed of a side marginal portion of the air-foil panel and a side marginal portion of an associated tether panel, said marginal portions being juxtaposed and secured together against relative movement.
 3. The kite structure of claim 2 in which said juxtaposed marginal portions are secured together by adhesive means.
 4. The kite structure of claim 3 in which the adhesive means comprises an adhesive layer interposed between said juxtaposed marginal portions.
 5. The kite structure of claim 3 in which the adhesive means comprises a tape spanning edges of said juxtaposed marginal portions.
 6. The kite structure of claim 2 in which the air-foil and the associated tether panels are formed of a single piece of sheet material folded to form said flanges.
 7. The kite structure of claim 6 in which the sheet material is selected from the group consisting of paper, plastic or fabric having stiffness substantially equivalent to 25 lb. M.G. Kraft or greater.
 8. The kite structure of claim 6 in which each flange includes longitudinally stiffening means interposed between said marginal portions normal to the lines of contiguity.
 9. The kite structure of claim 8 in which each said stiffening means comprises a strip of stiff sheet material.
 10. The kite structure of claim 8 in which there is a strip of tape spanning the length of each line of contiguity at the side margin of the air-foil panel. 